I'm Melissa Block, and we begin the hour with the latest developments in Iraq. The extremist Islamist group that's grabbed territory across much of that country and parts of Syria is now making grandiose claims of worldwide authority. They now claim to rule over all Muslims everywhere. They've changed the name of the group from the Islamic State of Iraq and Syria to simply the Islamic State. They say this is the dawn of a new caliphate, the old system of Muslim rule. To help explain this, we're joined by NPR's Alice Fordham who's in Baghdad. And, Alice, first when ISIS talks about restoring the caliphate, what exactly do they mean?

ALICE FORDHAM, BYLINE: Well, first I think it's important to say that this reflects the grandeur of their propaganda rather than necessarily the reality of their influence. Of course, the vast majority of the world's Muslims would reject this. But the reason they cite the caliphate is that a caliphate is a system of government used historically by Muslims, whereby there's one leader called a caliph who exercises control over religious and state affairs and which some very devout Muslims are nostalgic for. So what these extremists are doing by saying that what they have is a caliphate, is trying to paint these recent land-grabs not as a patchy takeover of territory that they've done with support of all kinds of different groups with different ideologies, but they're saying they've got instead the strong foundation for a unified Islamic state.

BLOCK: Well, Alice, the group has accomplished much of this - this land-grab - this territory that they've taken over with apparently just a few thousand fighters. To what extent can we say they actually have a state?

FORDHAM: Well, they claim in the statement that this - this state stretches from Aleppo in Syria to Diyala in Eastern Iraq, which if they did control all that territory, would be a quite a fair-sized country. And in a few places they do have kind of an organized system of rule, but in much more of that territory, they're battling other groups for control. In Syria, they're fighting Islamist rebel groups. In Iraq, they're fighting the army backed by Shiite militias. And with their recent dramatic moves in Iraq, they've prompted American officials, Russians, Iranian forces, to help the Iraqis to fight against them. So this is more propaganda than reality.

BLOCK: More propaganda, but is there a sense that something will change in terms of their tactics or practices?

FORDHAM: On a close reading of the statement, they talk a lot about practices that they're implementing already; they're not systematically or universally, like, destroying churches and shrines, taxing people that they called infidels, amputating limbs for various crimes, executions. One thing that is different is that they say now all other fighting groups are abolished, and everyone must pledge allegiance to them, specifically to their leader who's known as Abu Bakr al-Baghdadi.

BLOCK: And let's talk a bit more about him. Would you consider him now essentially the world's most influential violent Islamist extremist?

FORDHAM: Well, I think it's fair to say he's trying to be. Since Osama bin Laden was killed, al-Qaida has been taken over by Ayman al-Zawahiri, who many think has struggled to keep a hold on the group. When he told ISIS, this group, to leave Syria, they refused to do it. And so this is the latest and maybe the biggest in a series of challenges to al-Qaida, and it's been accompanied by outreach. A Yemeni official told me that Baghdadi sent invoice to Yemen to ask the al-Qaida members there if they wanted to go over to his side. And they're thinking about it.

BLOCK: And does this - this propaganda wave - this big talk - do you think convince would-be supporters to join the cause?

FORDHAM: Some of them, I think yes. Inside Syria, we have seen that some of the Islamist groups who previously rejected joining Baghdadi's group have now pledged allegiance to him. But there's also a lot that really fight against this idea and are repulsed by it still.